How Does a Below-Knee Amputation Work?


Transtibial amputation, or below-knee amputation, occurs when a surgeon fully removes a lower limb due to disease, a congenital defect, or trauma. Although amputation is possible for anyone of any age, the prevalence of this type of amputation is highest among people 65 years of age and older. In recent years, the number of below-knee amputations has diminished, and according to the National Center for Biotechnology Information, approximately 3,500 trauma-related amputations are performed each year in the United States.

What Is a Below-Knee Amputation?

A below-the-knee amputation involves removing the foot, ankle joint, distal tibia, fibula, and nearby soft tissue structures. The overall goal is to remove the unhealthy tissue and allow the leg to be more functional and cause less pain. Transtibial amputation is usually performed by an orthopedic or vascular surgeon. The surgeon removes the severely injured or damaged part of the limb and tries to keep as much of the healthy part as possible.

Why Would You Need a Below-Knee Amputation?

Some of the most common reasons for below-knee amputation include the following:

  • Diabetes.
  • Foot ulcers.
  • Infection.
  • Poor circulation, also known as peripheral vascular disease.
  • Trauma that caused the lower leg to be severed or crushed.
  • Tumors.

What Is the Surgical Process for a Below-Knee Amputation?

If you’re considering amputation, you should meet with a team of doctors who can help you make that decision. This team can include specialists such as a foot and ankle orthopedic surgeon, your physician, a prosthetist, a rehab doctor, and a physical therapist. They will all work together and decide on the best course of action regarding your leg. The surgery typically takes anywhere from 2 to 3 hours, depending on the patient.

Below-Knee Amputation Technique

During the surgical process, your leg is amputated to remove as much of the damaged area as possible. This type of amputation doesn’t have a specific length that works for all patients. However, several inches of leg bone located below the knee is necessary to properly secure an artificial leg. Having a longer residual leg doesn’t improve the ability to fit the prosthetic.

Each below-knee amputation is customized to the individual patient. Most patients remain asleep for the entire two- to three-hour procedure, although occasionally a spinal anesthetic or nerve block is enough. The surgeon makes an incision below the desired amputation location and cuts away the calf muscles and skin to create a flap. The bones are cut with a saw, and the surgeon might fuse the ends of the tibia and fibula in a procedure called the Ertl technique.

The surgeon then folds the remaining calf muscle up over the ends of the bones and keeps it in place with sutures. Staples or sutures are used to close the skin, and some surgeons will place a temporary drain to prevent blood from pooling near the amputated area. To reduce swelling and protect the leg, the surgeon might use a cast or compression dressing.

Below-Knee Amputation Post-Op Care

You should expect to stay at the hospital at least one night after the procedure is completed. You should be able to return home as long as you have assistance at home and can walk well with crutches or a walker. The surgical area will have a bandage, and you might have a drain positioned at the surgical site. Swelling is common and should subside after a few months. If you don’t have anyone at home or need more help walking, your team might recommend you stay in a rehabilitation facility until you’re ready to head home.

Your incision needs between two to six weeks to heal. The timing can depend upon several factors, including blood flow, medical conditions such as diabetes, and the overall condition of the skin and soft tissue. Once your doctor has cleared you for rehabilitation, you can begin physical therapy. The physical therapist will meet with you and discuss your medical and surgical history with you.

During your first few days of therapy, you might practice getting out of bed and move safely to a chair, perform gentle stretching exercises, and learn how to position your limb to straighten the knee joint fully without the lower appendage.

What Prosthetic Options Are Available?

someone being fitted for a prosthesis

Image via Flickr by University of Salford

You might be fitted with a transtibial prosthetic within three months post-surgery, but don’t expect to walk in it until the area heals completely. This timeframe is typically between six to 12 months. This type of prosthesis replaces the function of the missing segment from below the knee to the floor. It typically features a custom-made socket, pylon, and prosthetic foot. The prosthetist will create an individualized socket that is specific to your limb that caters to your specific lifestyle and activity level.

The process for obtaining a long-term prosthesis might take a while simply because it’s vital to obtain the right product and secure the right fit. Since your limb changes in shape and size for the first six months after surgery, it’s important to wear additional levels of socks over your limb to prevent the socket from becoming too loose or add padding to the socket to improve the fit.

Often, the pylon found on the initial prosthesis doesn’t feature a cosmetic covering, so your prosthetist can easily make changes to the socket or adjust its alignment. Once your residual limb stops shrinking and you’re able to resume a moderate level of activity, your prosthetist might decide it’s time to move to a definitive prosthesis.

For this type of prosthesis, you can expect to meet with your prosthetist several times. You should receive the prosthesis in a few weeks, and depending on your daily use and activity level, it should last two to five years. This mechanical device might need adjustments and repairs, so make sure you pay attention to its operation.

If you need a prosthetic after your below-knee surgery, reach out to the professionals at Scheck & Siress. Since our founding in 1953, we’ve remained committed to delivering quality care to all our patients. We provide superb pre- and post-operative patient care for prosthetics so that our patients can improve and restore their mobility. Contact us today to learn more about how we can help with your recovery.